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Shear walls have high strength and stiffness, which could be used at the same time to resist large horizontal loads and weight loads, making them pretty beneficial in several structural engineering applications. The shear walls could be included with openings, such as doors and windows, for relevant functional requirements. In the current study, a building of G + 13 stories with RC shear walls with and without openings has been investigated using ETABS Software. The seismic analysis is carried out for the determination of parameters like shear forces, drift, base shear, and story displacement for numerous models. The regular and staggered openings of the shear wall have been considered variables in the models. The dynamic analysis is carried out with the help of ETABS software. It has been observed that shear walls without openings models perform better than other models, and this is in agreement with the previous studies published in this area. This investigation also shows that the seismic behaviour of the shear wall with regular openings provides a close result to the shear wall with staggered openings. At the roof, the displacement of the model with regular openings was 38.99 mm and approximately 39.163 mm for the model with staggered openings. However, the model without a shear wall experienced a displacement of about 56 mm at the roof. Generally, it can be concluded that the openings have a substantial effect on the seismic behaviour of the shear wall, and that should be taken into consideration during the construction design. However, the type of opening (regular or staggered) has a slight effect on the behaviour of shear walls.

The present study focuses on the effect of cement replacement with micro-silica fume (SF), nano-silica fume (NS) and fly ash (F) individually and in a combination of two additives, on the mechanical properties (split, flexural tensile and compressive strengths) of 22 modified concrete mixes. The microstructure analysis and chemical microanalysis of the mixes have also been undertaken. The addition of micro- and nano-silica fume alone enhances the strength of concrete. However, the addition of fly ash causes a reduction in the strength properties for all replacement percentages. The combination of micro- and nano-silica fume improves the mechanical properties of concrete for all percentages of replacement. The microstructure and chemical analysis of modified concrete show enhancement in the morphological properties of concrete owing to pore filling with dense and compact structure and C–H crystals reduction and denser structure in pastes due to the incorporation of micro- and nano-silica fume. The present experimental research shows that the concrete modified with industrial by-products establishes extra functionalities, thus well addressing the environmental sustainability issues.

Numerical and experimental investigation of reinforced geopolymer concrete (RGPC) beams containing steel fibres with loads placed at different span-to-depth ratios is presented in this study. Analytical investigations on RGPC beams with different load geometries are undertaken using nonlinear finite element analysis. ABAQUS software is employed for general-purpose finite element modelling (FEM) and analysis. The material properties of concrete in compression and tension and steel reinforcement used for modelling are presented. Types of constraints provided for FEA between concrete and steel are explained. The four-point test and finite element analysis have been performed to investigate the mechanical performance of RGPC beam specimens and compare the experimental results with the analytical outcomes. The effect of position loads at various span-to depth ratios on ultimate load, deflection, and crack manners are discussed. The results indicate that the modulus of elasticity and compressive strength of RGPC is improved due to the incorporation of steel fibres. The failure pattern of the RGPC is similar to the conventional concrete. The FEM proves its potential for predicting the behaviour of RGPC beams and the pattern of failure. Furthermore, the experimental findings are found to be in good agreement with the results of the FEM.

In recent years, steel-concrete composite shear walls have been widely used in enormous high-rise buildings. Due to their high strength and ductility, enhanced stiffness, stable cycle characteristics and large energy absorption, such walls can be adopted in auxiliary buildings, surrounding the reactor containment structure of nuclear power plants to resist lateral forces induced by heavy winds and severe earthquakes. The current study aims to investigate the seismic behaviour of composite shear walls and evaluate their performance in comparison with traditional reinforced concrete (RC) walls when subjected to cyclic loading. A three-dimensional finite element model is developed using ANSYS by emphasising constitutive material modelling and element type to represent the real physical behaviour of complex shear wall structures. The analysis escalates with parametric variation in reinforcement ratio, compressive strength of the concrete wall, layout of shear stud and yield stress of infill steel plate. The modelling details of structural components, contact conditions between steel and concrete, associated boundary conditions and constitutive relationships for the cyclic loading are explained. The findings of this study showed that an up to 3.5% increase in the reinforcement ratio enhanced the ductility and energy absorption with a ratio of 37% and 38%, respectively. Moreover, increasing the concrete strength up to 55 MPa enhanced the ductility and energy absorption with ratios of 51% and 38%, respectively. Thus, this improves the contribution of concrete strength, while increasing the yield stress of steel plate (to 380 MPa) enhanced the ductility (by a ratio of 66%) compared with the reference model. The present numerical research shows that the compressive strength of the concrete wall, reinforcement ratio, layout of shear stud and yield stress of infill steel plate significantly affect ductility and energy absorption. Moreover, this offers a possibility for improving the shear wall’s capacity, which is more important.

In the present paper, nonlinear time history and response spectrum analyses were carried out using Etabs-2015 software to study the influence of soil condition beneath the isolated base. The effects of soil flexibility are considered in the current study to examine the differences in spectral acceleration, base shear, story displacements, story drifts and story shear obtained following the seismic provisions of Indian standard code. Various soils are systematically compared and discussed for a seismic performance of multistory buildings. Parametric analysis of the buildings fitted with isolation devices is carried out to choose the appropriate type of soil. The study shows that the value of base shear increases with an increase of soil flexibility and superstructure stiffness. It also observed that the spectral acceleration (SA) and spectral displacement (SD) are higher in soft soil condition, which gives us evidence that the response spectral of a structure is associated with soil condition. The paper concluded that the hard soil and medium soil are suitable for base isolation building. In addition, analysis and design considerations for base isolated and conventional structures are suggested to enable the designer to get a better understanding at the preliminary design stage.